Over-current protection is traditionally provided by fuses or circuit breakers which require thermal or electro-magnetic delay intervals for operation. Prior art over-voltage protectors generally are not capable of handling heavy current. Thus, a need exists for an over-current protector which provides instantaneous over-current protection, and which will augment or work in cooperation with an over-voltage detector to protect both the circuit and over-voltage device against high-current surges.
The present invention provides the following advantages over current state of the art devices;
(a) it provides instantaneous protection at an electronic speed for the protected circuit, unlike the prior art devices which are inherently limited to thermal or electro magnetic delays; PA1 (b) it additionally provides over-voltage protection, providing isolation for the equipment or the protected line from the source until the over-voltage condition has subsided; PA1 (c) both the over-current and the over-voltage protection is fully automatic and does not need to be manually reset. The device periodically samples the source and load and continues to interrupt the primary line until the over-voltage or over-current condition has subsided.
The present invention is particularly applicable and useful for a wide variety of electrical applications, and may be provided as an AC circuit breaker, a DC circuit breaker, or an AC-DC circuit breaker.
The AC circuit version is particularly applicable to household and industrial application, particularly where large industrial motors or transformers are involved.
The DC circuit version is particularly applicable to automotive applications and industrial power supplies for computers and other voltage sensitive DC circuits.
The AC-DC circuits are particularly useful for the telecommunications industry, and power companies as surge protectors used to protect telecommunication lines and AC lines against lightning surges or other uncontrolled voltage and/or current-overloads.